Ebb, Flow and crash

This year was also the year of the GRAIL mission, which launched at the end of 2011. NASA's Gravity Recovery and Interior Laboratory craft were sent into space for a lunar study mission and met up to orbit the moon in January.

GRAIL-A, later known as Ebb, had already reached the Moon on New Year's Eve and GRAIL-B, later known as Flow, joined it a few days later. The twin flyers, named in a competition, then manoeuvered into formation flying positions to reduce their orbital period to just under two hours in order to map the rocky body's gravitational field.

The two probes, in a near-polar, near-circular orbit around the Moon, were the first attempt by NASA of such orbital precision. Engineers had to take into account the pressure effects of sunlight, both directly and bouncing off the Moon, along with heat radiation from the Moon and the crafts, minute amounts of gas escaping from the craft and the expansion and contraction of various parts of the ship in response to heating and cooling.

When large changes show up in the gravity field, boffins can piece together surface topography like craters or mountains, as well as tectonic structures, volcanic landforms, basin rings and crater central peaks. The boffins found that the Moon's crust is actually around 10km to 20km thinner than previously thought.

After their mission was complete, NASA decided on a novel way to finish with Ebb and Flow - crashing them into the Moon's surface. With the GRAILs' lifespan coming to an end, the agency got them to burn out all their remaining fuel, allowing engineers to match the actual fuel they had left to their estimates. Both craft were then flung manually at the dark side of the Moon.

NASA had the biggest mission of the year on its hands with Curiosity, but plenty of other people were making strides in space this year. If there were a non-government-affiliated Man of the Space Year award, it would undoubtedly have gone to Elon Musk, whose SpaceX firm became the first private company to supply the International Space Station.

The Dragon made an understandably cautious approach to the station, first doing a flyby within 1.5 miles (2.5km) of the ISS to ensure that 'nauts onboard were able to take remote control of the capsule. The cargoship then edged closer and stopped for some adjustments, then to within 30m of the station and stopped again, before finally reaching the 10m point where the Canadarm could grab it.

Flight Engineer Don Petit helped make history by reaching out with the robotic arm and snagging the Dragon at just before 15.00 GMT on 25 May. Whether it was down to his own rapier wit, or the combined punning abilities of NASA engineers and boffins, Petit had the perfect line for the occasion:

"Looks like we've got a dragon by the rail," he told Mission Control in Houston.

But SpaceX isn't above the technical issues that all space ventures have. The second launch of a supply ship to the ISS didn't go as well as the historic first, leaving a commercial satellite stuck in the wrong orbit.

The Falcon 9 rocket suffered an engine failure as it started the climb towards space that kept the Dragon craft on track but dumped Orbcomm's sat early. Unfortunately for Orbcomm, the satellite couldn't recover and it was burnt up in the atmosphere a few days later.